Add tests for MibScalarInstance to validate noSuchInstance behavior

Author: lextm

tests/smi/test_snmpv2_smi_scalar_instance.py

@@ -0,0 +1,53 @@
+import pytest
+
+from pysnmp.proto.api import v2c
+from pysnmp.smi.builder import MibBuilder
+from pysnmp.smi.error import NoSuchInstanceError
+
+
+def _make_mib_scalar_instance(syntax):
+    mib_builder = MibBuilder()
+    mib_builder.loadTexts = True
+    _, MibScalarInstance = mib_builder.import_symbols(
+        "SNMPv2-SMI", "MibScalar", "MibScalarInstance"
+    )
+    return MibScalarInstance((1, 3, 6, 1, 2, 1, 1, 1), (0,), syntax)
+
+
+def test_schema_only_scalar_instance_read_get_raises_no_such_instance():
+    scalar = _make_mib_scalar_instance(v2c.Integer())
+
+    assert scalar.syntax.isValue is False
+
+    with pytest.raises(NoSuchInstanceError):
+        scalar.readGet((scalar.name, None))
+
+
+def test_schema_only_scalar_instance_read_test_next_raises_no_such_instance():
+    scalar = _make_mib_scalar_instance(v2c.Integer())
+
+    assert scalar.syntax.isValue is False
+
+    with pytest.raises(NoSuchInstanceError):
+        scalar.readTestNext((scalar.name, None), oName=(1, 3, 6, 1, 2, 1, 1, 0))
+
+
+def test_schema_only_scalar_instance_read_get_next_raises_no_such_instance():
+    scalar = _make_mib_scalar_instance(v2c.Integer())
+
+    assert scalar.syntax.isValue is False
+
+    with pytest.raises(NoSuchInstanceError):
+        scalar.readGetNext((scalar.name, None), oName=(1, 3, 6, 1, 2, 1, 1, 0))
+
+
+def test_value_scalar_instance_read_get_returns_value():
+    scalar = _make_mib_scalar_instance(v2c.Integer(5))
+
+    assert scalar.syntax.isValue is True
+
+    name, value = scalar.readGet((scalar.name, None))
+
+    assert name == scalar.name
+    assert value.isValue is True
+    assert int(value) == 5